This invention relates to the treatment of diseases induced by biochemicals released from activated mast cells. More particularly, the invention relates to treatment of mast cell-induced diseases such as allergies, interstitial cystitis, inflammatory bowel disease, irritable bowel syndrome, and certain hyperproliferative diseases such as systemic mastocytosis with a proteoglycan without or with functionally synergistic flavonoids and/or heterocyclic antagonists of histamine receptors.
Mast cells are a normal component of connective and mucosal tissues and play an important role in allergy and inflammation. They are localized in the connective tissues, but also in the mucosa of the bladder, gastrointestinal tract, lung and nose, as well as in the skin and the meninges of the brain. They are located there because these tissues are the main entry points for infective organisms, allergens and other noxious chemicals that trigger the body""s immune response.
Mast cells derive from the bone marrow and migrate into the tissues where they synthesize and can secrete numerous vasoactive, nociceptive and inflammatory mediators. (Galli, S. J. N. Engl. J. Med. 328:257, 1993). They are located perivascularly close to nerve endings and can be activated by a variety of neuroimmunoendocrine triggers. (Theoharides, T. C. Int. J. Tissue React. 18:1, 1996).
Mast cells are located at strategic points around capillaries and small blood vessels, where they are important in regulating the extent of constriction or dilation of the vessels including those which make up the blood-brain barrier, the protective lining of the brain which excludes toxic materials (Theoharides, T. C., Life Sciences 46:607, 1990).
Each mast cell contains up to 500 secretory granules, each storing more than 20 potent biological compounds. Mast cells secrete the contents of these granules (i.e., degranulate) when triggered by various specific and non-specific mechanisms, such as the allergic reaction involving immunoglobulin E (IgE) and antigen (Ag). Notable among non-allergic triggers are certain polysaccharides or monosaccharide-containing lectins such as dextran and concanavalin A (Baxter, J. H. et al, Biochemical Pharm. 27:497, 1978). Other known triggers include the neurotransmitter acetylcholine, various neuropeptides such as calcitonin-gene-related peptide (CGRP), corticotropin-releasing hormone (CRH), neurotensin (NT), substance P (SP), somatostatin and vasoactive intestinal peptide (VIP), as well as viruses, bacterial toxins, drugs (such as aspirin, morphine and curare), contrast media used in radiology, extreme heat, cold, solar radiation, hyperosmotic media and pressure (Theoharides, ibid.).
Compounds released by mast cell degranulation, collectively referred to as mediators or activators, include: histamine, kinins, prostaglandin D2 and vasoactive intestinal peptide, which are vasodilatory, as well as serotonin, prostaglandin F2-alpha and leukotrienes, which are vasoconstrictive. In addition, cytokines, histamine, kinins and prostaglandins can cause pain directly, while enzymes that destroy proteins and phospholipids can cause tissue damage directly. Finally, cytokines can cause inflammation and regulate other biological responses (Galli, S. J., above).
The compounds released by the mast cells following degranulation are known to cause many biological responses which are part of the overall response of the body to invasion by infective organisms, allergens or other stressful stimuli. Degranulation will be defined herein as the release of any or all mediators from any or all secretory granules, whether in parallel, sequentially, differentially or selectively. Relevant examples of such responses are vasodilation and recruitment of inflammatory cells (e.g. leukocytes) from the circulation, tearing, nasal secretions, bronchoconstriction, itching of the skin, diarrhea or bladder pain.
Histamine and the other mediators are secreted from the granules of mast cells during degranulation. The histamine and other mediators then bind to specific receptors on the surface of endothelial cells on vessels, neurons or other tissues. Vasodilation and chemoattraction permits lymphocytes to leave the blood circulation and enter the tissue, where they cause additional mast cell degranulation and other responses. The process of degranulation continues, eventually involving many mast cells. It is important to note that there are no clinically available drugs with mast cell secretion inhibitory activity. Anti-histamines, properly known as histamine receptor antagonists, act only after histamine is released (Theoharides, T. C., Drugs 37:345, 1989). They neither block the secretion of histamine or other mediators nor the action of any other mediators. Disodium cromoglycate (cromolyn) is called a xe2x80x9cmast cell stabilizerxe2x80x9d and is available for rhinitis, asthma and food allergies, but its action is short-lived, it is only partially effective, it does not affect all mast cells and it is difficult to put in solution (Shapiro, G. G. et al., Pharmacotherapy 5:156, 1985).
The common form of interstitial cystitis (IC) is the xe2x80x9cearlyxe2x80x9d or non-ulcer variety with normal bladder capacity and the absence of inflammation. The role of mast cells in the bladder has acquired increased significance since it was shown that mast cells in this tissue can be activated with or without an increase in their numbers (Theoharides, T. C. et al., Sem. Urol., 9:74, 1991). Moreover, acute immobilization stress results in bladder mast cell degranulation (Spanos et al., J. Urol.,157:669, 1997).
Mucosal mast cells have also been implicated in irritable bowel syndrome (IBS) (Weston, A. P., et al., Digestive Diseases and Sciences 38:1590, 1993) where are increased in numbers and/or activated to various degrees. (Pang, X. et al., Urology 47:436, 1996). Moreover, histamine and prostaglandins have been involved in gastrointestinal permeability and related diarrhea syndromes. (Castaglluolo, I. et al., Am. J. Physiol. 271:884, 1996). Recent studies have shown that acute stress by immobilization leads to gastrointestinal mast cell activation, a process blocked by pre-treatment with neutralizing antiserum to corticotropin releasing hormone (CRH) which is liberated under stress (Castaglluolo, I. et al., above). We further showed that CRH can induce mast cell degranulation and increased vascular permeability directly (Theoharides, T. C., et al., Endocrinology 139:403, 1998).
The term inflammatory bowel disease (IBD) is used to describe a variety of disorders. Crohn""s disease, as well as various forms of infectious diarrhea, such as that due to Clostridium difficile which is called pseudomembranous colitis, are the most common forms of inflammatory conditions of the intestine. Recent evidence (discussed above) indicates that mast cells exist in the mucosa of the small intestine and that they are different from mast cells in other, especially connective tissues. Moreover, they have also been shown to be in close apposition to nerve endings, suggesting that they may be affected by the nervous system. In fact, gastrointestinal membranes are activated in Crohn""s disease (Dvorak et al., Int. Arch. Allergy Immunol., 98:158, 1992).
Mast cell secretion was shown to be stimulated by parathyroid hormone (PTH) in vitro (Tsakalos, N. D. et al., Biochemical Pharmacology 32:355, 1983). In addition, PTH was shown to increase mast cell accumulation in bone (Rockoff, S. D. et al., Calc. Tiss. Res. 5:49, 1970). Molecules secreted from mast cells may increase bone resorption, leading to a net loss of bone loss, and eventually resulting in osteoporosis in susceptible individuals. In fact, osteoporosis was seen as the sole presentation of bone marrow mastocytosis in humans (Lidor, C., et al., Journal of Bone and Mineral Research 5:871-876, 1990). During an investigation of the bone response to calcium deficient diets over time, dramatic increases in the numbers of mast cells were observed in the metaphyseal region of tibia, which showed osteitis fibrosa, and eventually net loss of bone. Finally, there have been several recent case reports of systemic osteoporosis associated with systemic mastocytosis (Chines, A., et al., Journal Clin. Endocrinol. Metab., 72:140, 1991;Longley et al., J. Am. Acad. Dermatol. 32:545, 1995).
Scleroderma is an autoimmune disease which occurs five times more often in women than men. It involves the whole body, but it primarily manifests itself on the skin which is progressively replaced by fibrotic tissue giving a hardened and aged appearance. Other peripheral manifestations are Raynaud""s phenomenon, which is characterized by intense vasoconstriction of the hand vessels leading to anoxia and pain. Mast cells have often been associated with this disease (Siebold, J. R., et al., Arthritis and Rheumatism 33:1702, 1990;Irani, A-M., et al., Arthritis and Rheumatism 35:933, 1992). There is no effective therapy for this condition even though calcium entry blockers such as nifedipine and verapamil have been used.
Proteoglycans are high molecular weight polyanionic macromolecules (heteropolysaccharide) consisting of many different glycosaminoglycan chains linked covalently to a protein core that constitutes up to about 5% of the total macromolecules. Monosaccharide components of proteoglycans, such as glucosa nine sulfate or N-acetyl-D-glucosamine are also available commercially. Six distinct classes of proteoglycans are now recognized: chondroitin sulfate, dermatan sulfate, heparin and its sulfate, keratin sulfate, and hyaluronic acid. (For structures, see xe2x80x9cTextbook of Biochemistryxe2x80x9d, T M Devlin, ed., John Wiley and Sons, N.Y., 1986, pp 347-351); Chondroitin sulfate, like the other proteoglycans, is naturally occurring, and is a natural constituent of connective tissues. It is available over the counter as a food supplement (e.g. INHOLTRA, Kennebunk, Me. 04043 or AMERIFIT, Bloomfield, Conn. 06002).
Flavonoids have been reported to inhibit mast cell secretion (Middleton, E. et al, Biochem. Pharm. 43:1167, 1992). However, the only patented use of flavonoids is the use of the flavonoid kaempferol for a dermatological preparation to stimulate skin pigmentation or superficial body growth (WO90/06104, Jun. 14, 1990). Flavonoids are naturally occurring molecules. The average daily U.S. diet contains about 1 g of mixed flavonoids. However, certain concentrated flavonoids are being sold over the counter as food supplements (e.g. pycnogenol, 25 mg capsules by Country Life, Hauppauge, N.Y. or quercetin 300 mg caplets by Allergy Research, Grove Calif. or Freeman Industries, Tuckahoe, N.Y.).
However, neither proteoglycans without or with flavonoids have been described for therapeutic use in any of the clinical conditions described above.
The invention provides a method for preventing and treating the harmful biological effects of secretion of biochemicals from mast cells in the organs of warm blooded animals and more especially human beings. These harmful biological effects include allergy (including butriot limited to allergic conjunctivitis, allergic rhinitis, allergic otitis, asthma, and atopic dermatitis) interstitial cystitis, inflammatory bowel disease, irritable bowel syndrome, scleroderma, osteoporosis, and hyperproliferative diseases such as systemic mastocytosis and leukemia.
In one aspect of the invention, the method consists of administering to said animals and especially to human beings an amount of a proteoglycan with mast cell secretion inhibitory activity, such as chondroitin sulfate, keratan sulfate, and dermatan sulfate.
In a second aspect of the invention, the method consists of administering a proteoglycan combined with one or more synergistic adjuvants (such as those belonging to the class of flavonoids (such as myrisetin, quercetin, genisetin or kaempferol) or heterocyclic compounds with histanine-receptor antagonist activity.
These and other aspects will become clear by reference to the specification and appended claims.
It has been unexpectedly discovered that diseases resulting from the biochemicals released from activated mast cells can be successfully treated with proteoglycans alone or together with one or more synergistic adjuvants such as flavonoids and heteroyclic compounds with histamine receptor antagonist activity.
The method of the present invention consists of the daily administration to patients suffering from an allergic condition of about 100 to about 5,000 mg of a proteoglycan such as chondroitin sulfate. The oral route of administration or local application to affected areas is preferred so that the patient can self-medicate.
In accordance with the present invention, proteoglycans may be administered to patients in any conventional oral or parenteral dosage form that will make the drug most available to exposed mucosal or skin surfaces. Oral dosage forms may include tablets, capsules, caplets, liquids and the like, including generally from about 200 to about 2,000 mg of chondroitin sulfate per dosage unit together with flavonoids and/or the heterocyclic compounds claimed and suitable pharmaceutically acceptable excipients, binders, sweeteners, coloring agents and other conventional additives. Parenteral dosage forms may include any conventional solutions of chondroitin sulfate, for example, an isotonic saline solution together with pharmaceutically acceptable preservatives and buffers. The parenteral dosage forms generally contain from about 50 to about 250 mg of chondroitin sulfate and may be administered with a dropper for allergic conjunctivitis, spray for allergic rhinitis, inhaler for allergic asthma, intravesically for interstitial cystitis, or with a cream or ointment for allergic dermatitis or allergic urticaria.
In one preferred method, a proteoglycan may be initially administered orally to patients in daily doses of about 500 mg each, with gradual increments up to a maximum of 2,500 mg b.i.d.
Where indicated, flavonoids or histamine recptor antagonists are administered together with a proteoglycan, at doses of about 2500 mg proteoglycan, about 500 mg flavonoid and/or about 50 mg of a histamine-1 receptor antagonist.
The method of the present invention also provides dramatic symptomatic relief for patients suffering from interstitial cystitis and irritable bowel syndrome even where conventional modalities of treatment have failed. Patients receiving chondroitin sulfate treatment experience a decrease in urinary and bowel movement frequency respectively and associated pain because of additive actions not found in any other approved or experimental medication: a) inhibition of secretion from mucosal mast cells that have been found to proliferate and be activated in the bladder wall of patients suffering from interstitial cystitis and the intestinal wall of patients suffering from irritable bowel syndrome b) forming a protective layer covering the mucosal surface of the bladder and the intestine.
The method of the invention can also be used to prevent or treat mast cell secretion-related diseases such as osteoporosis, scleroderma (or, systemic sclerosis). Further, the method of the invention can be used to treat hyperproliferative diseases involving mast cells, such as leukemia and systemic mastocystitis.